Talking motion picture projector



Aug.16', 1932. l R, RMAY 1,871,716

TALKING MOTION PICTURE PROJECTOR origingl Filed sept. 12. 1929 BY M7/MJ ATIQRNEY Patented Aug. 16, 1932 UNITED STATES PATENT OFFICE RUSSELL?. MAY, 0F HADDONFIELD, NEW JERSEY, ASSIGNOR TO RADIO CORPORATION 0F AMERICA, A CORPORATION 0F DELAWARE TALKING MorIoN PICTURE :enogncron Original application led September 12, 1929, Serial No. 392,051. Divided and 'February 17, 1931.

In the past, a machine for projecting motion pictures has required many specialfadjustments and manipulations, and is altogether so complicated that it requires a more or less experienced operator in order to properly operate'it. This has been a serious drawback in the development of the home motion picture field, as the difficulty experienced by the home operator often precludes a thorough enjoyment of motion pictures in the home.

With the advent of talking motion' pictures,

Athis problem has been increased, because of the fact that a more complicated arrangement. is necessary, due to the additional con? tinuous motion oftheI iilm past the sound reproducing apparatus.

Various machines have been proposed for accomplishing the threading of amotion picture projector automatically, or more com-v monly, in a semi-automatic manner, that is, in a manner requiring simple manipulation but not requiring adjustments.

It is, therefore, the primary object of the present invention to produce a machine which is entirely automatic, that is one in which-all -of the manipulations, as well as the adjustments, are donewithout the aid of the operator. This 1s, so far as the inventor 1s aware,

the first talking motion picture machine in motionpicture projector which may be readily threaded by an inexperiencel operator.

Still another object of this invention isto provide means whereby the film maybe connected -to a -take-up reel automatically, requiring no control on the part of the operator.

Astill further object of this invention is to provide a new and improved film take-up ree These vand additional ob'ects of my invention w1ll become apparent rom the following `the action of film loops.

Serial No. 516,359.

is arranged with certain movable-portions so that, after the film has passed through the -said channel and the projection is ready t0 commence, these portions of the channel are automatically moved so as to permit the film this applieatnmv mea' to be moved intermittently' and to permit The lilm is guided from the lower continuously rotating sprocketto the take-up reel where a hole in the end of the film is caught by a spring pressed plunger in the hub of the reel. A plurality of similar springpressed plungers, arranged around the periphery of the drumx' are depressed into the hub by the pressure "Tof the film as it surrounds t-he hub. As the reel rotates, the guide which guided the film into contact with its hub, is caused to move by the increasing amount of film being built up. When this motion has been sucient,`the guide is automatically released and moves, under the pressure of a spring to an inoperative position.

Having thus briefly described my invention, reference is now invited to the accompanying drawing wherein: I

Fig. 1 is a general elevation showing the principal elements embodying my invention; and,

Fig. 2 is a detail of the take-up reel.

Attention is now particularly invited to 1, wherein 2O represents the frame of the machine. For `furnishing the light for projecting the pictures, there is provided a lamp .housing 21 equipped with condensing lenses, lamps, etc., the details of which are well known in the art and form no part of the present invention. I

The supply reel for the film is shown at 22 above the frame of the machine, and the takeup reel is shown at 23. l

For removing the film from the reel 22 and passing it through the machine, in the thread- `ing operation, as well as during running,

there is 'provided' a continuously rotating sprocket 24. For 'pulling the lm through the lower part "of the machine, and more particularly around the reproducing drum, there is provided a similar continuously ro tating sprocket 25. These two sprockets are driven by a common shaft rotated by a motor of any appropriate design. The sprocket 25 is driven through a mechanical filter which will be described more in detail hereinafter.

T he details of the driving mechanism, except as just noted, constitute no part of the present invention and are therefore not being described.

j As part of the drivin mechanism of the continuous motion sproc iet 25, there is provided a iywheel 26 which is directly connected to the shaft of the said continuously rotating sprocket 25, and which is driven by 4a positivelyI driven grid member through a from the source 29 is focussed upon the film,

92 at the film gate 31 by means of the lens i, system 32. For projecting theimage of the illuminated film upon the photoelectric cell 34, there is provided an optical system including the objective lens 33. The construction of 'this optical system is well known and it includes a screen having a slot therein upon which the image of the film is focussed'.

The llight from this slot is 'focussed upon the' photoelectric cell and variations of the light intensity vary the latters resistance to opcrate a sound reproducer.

For preventing any effect of the intermittent motion of the film at the picturev gate 27 from reaching the film at the sound gate 31,

and also for holdingthe film in contact with the reproducing drum 30, there is provided the damping roller 35 against which the film is pressed by the pressure roller 36.' The pressure roller 36 is mounted upon an arm of the threading release operating lever 37, which latter is pivoted at 38 and so arranged as to cause the pressure roller 36 to be pressed against the film by spring 39. v

Forl guiding the film into contact withthe upper continuously rotating sprocket 24,

l there is provided a funi'iel-sliaped` guide 4'0.

`After passing the sprocket 24 the film is guided through the upper loop guide 41 which includes a movable section 42 which Vmay be moved vfrom the position shown` in stiffness to move the trig er heavy es to that shown indotted lines. The film-is thus passed between the separable parts of the picture gate 27 and through the lower loop guide 43 which latter includes a second movable section 44 which ma be moved from the position shown in heavylines to that shown in dotted lines.

For' guiding the film around the sound reproducing drum 30, there is guide 45, which it is to be noted-1s disposed at the lower portion thereof, a greater distance from the surface of the drum than at other portions. This is for the purpose of later permitting an accumulation ofthe film between the film picture ate 27 and the dampprovided the ing roller 35, as will e explained more 1n detail hereinafter. For guiding the filmV from the reproducing drum 30 to and around the continuously rotating sprocket 25 there is provided the guide 46 through an aperture in which projects the'releasing trigger 47.

The trigger 4 during the threading operation engages the catch 48 on the threading release operating lever 37; it being presse into engagement with said catch by means of the trigger spring 49.

The film while being passed around sprocket` 25, being bent in a curve, has suiicient 47, and after the lever 37 has been move by the spring 39 into the operating position there is no longer a pressure by the trigger spring 49 upon the tr1gger'47, so that the latter does not press upon the film.

1 For attachingthe end of the film to the take-up reel 23, there is provided a take-up mechanism 50 which will be described more in detail hereinafter.

Fig. 2 shows the details of one of a plurality of pins inserted in the hub of the take up reel 23 of Fig. 1. The take-up reel has a hub 125 vin an aperture 127 of which is f inserted the spring 4pressed plunger' '126. This plunger 1s pressed by means of the spring 128 acting against the collar 130 so that its end 129 willfproject a considerable distance beyond the surface of the hubv 125. For retaining thev plunger in the hub, there is provided a bushing,r 131 which limits the amount -which the pin 129 may project, by cooperation with the collar 130. One of the several pins 126 will 'engage 'a hole cut in the end of t eral speed of the hub is greater than the linear -speed ofthe end of the film. The second layer of the film 92 will cause the'pin to be de.- pressed against thepressure of the spring e film due to the fact that the periph 128 until it is in the position shown. The i remaining pins willbe depressed by the film until they are flush with the surface ofthe hub.

pivotally mounted the curved lower guide member 234.v The arm 236 projecting from the lower guide member 234 imparts motion At the lower end of the member 50 is chine is pulled down manually and held there j in the position shown in Fig. 1 by the latch 47-48. The trigger 47 has a lever which lies in a central'portion of the lower continuously rotating sprocket. As the film is picked up by this sprocket and carried 4around it, it is also carried under this trigger and, due to the stiffness tcreated by the film being bent around the sprocket, the film is able toraise the trigger and unlatch the lever 37. During the picture projection, the trigger 47 has no spring tension which would hold it against the film, the tension for holding the trigger into position being supplied by the trigger spring 49 mounted on the lever 37 which when in the raised positionis notin contact with the trigger 47. The upper take-up guide 50 is of channel crosssection, and the bottom guide 233 cooperates therewith to direct the film toward the hub of the drum. Ata plurality of points around the periphery of the hub of the takeup reel as is described above, are located spring-pressed plungers whose ends project about 1A; of an inch above the surface of the hub of the drum', and as the film is fed down to the drum and partiallyaround it by the 40 curved portion of the lower take-up Yguide 234, one of these plungers engages in a hole in the end of the film dueto the fact that the drum is driven at a slightlygreater speed than the film. The cross-section of this lower take-up guide is so designed as to allow these plungers to pass freely even though the guide is in contact with the hub at its edges. After the film has become engaged with a plunger and is securely caught thereto, the film is automatically put under tension which is sufficient to depress all the succeeding pins and also to 4cause the second layer vof film to depress the pin which caught the end of the film. l

After a predetermined amount of the film has been wound up on the reel, its diameter is increased to a degree which causes the lower guide to be lifted up vabout 'the hinge 235 and thereby cause the guide mechanism to be unlatched. Then, due to the action of the spring 240, the take-up guides are moved to the position which position permits them to clear the take-up reel.

Various modifications'may come within the scope of my invention as defined by the above objectsv and described in the accompanying specification and it is to be understood that I am not to be limited by the specific embodiment shown and described solely for the purpose of illustration, but by the scope of the invention as set forth in the appended claims.

l. A take-up reel for use in an automatic motion picture projector which comprises a hub portion, a plurality of 'plungers mounted .in said hub portion, one of which is adapted to catch a hole in the lend of the film being fed thereto and each having a head portion normally adapted to be raised above the surface of said hub, a spring for normally pressing said` plunger so that its head protrudes above the surface of said hub, and a bushing for retaining said plunger in said hub whereby a film being accumulated on said hub will press each `of said plungers into said hub against the pressure of said springs.

2. A take-up reel for use in an automatic motion picture projector which comprises a hubportion, a plurality of plungers mounted in said hub portion, one'of which is' adapted to catch a hole in the end of a film being fed thereto, and each having a head portion normally adapted to be raised above the surface of said hub, and a spring for normally pressing said spring-pressed plunger so thatits head protrudes above the surface of said hub, whereby a film being accumulatedon said hub will press each of said plungersmto said hub against the pressure of said springs.

3. A take-up reel for use in an automatic motion picture projector which comprises a hub portion, and a plurality of springpressed plungers mounted in said h ub portion whereby a film being fed onto said take-up reel will be caught by one of said plungers in a hole in the end therein, and the film ac-l cumulated on said hub will pressv said plungers into said hub.

4. A take-up reel for use i n an automatic motion picture projector which comprises a hub portion, mounted Iin said hub portion-whereby a film being fed onto said take-up reel will caught in a hole in the end thereof by said plunger and the next turn of film accumulated on said hub will press said plunger into said hub flush with the ltop of the first turn of film. RUSSELL Pi MAY.

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and a spring-pressed plunger 

